One commonly-used strategy in charitable fundraising is sharing names and contact information of donors between organizations, even those whose missions are unrelated. The efficacy of this practice hinges on the existence of “giving types,” that is, a positive correlation at the individual...

This paper examines the impact of social comparisons on fundraising and charitable contributions. We present results from a field experiment involving contribution to a public radio station. Some callers are told of the contributions decisions of others, and other callers are given no such...